I have to disagree with the previous posting. First of all, Zillow is not a reliable source for determining value, in my opinion. One can look at Zillow to see recent sales to get a rough indication of market value, but not for allocation of value, especially for tax purposes.
For tax purposes, if the property was unimproved land it is likely to have a different base year than improvements (such as a home) that are constructed years later. If the property was already improved (with a home) then different areas may have different land allocations for tax purposes. For example, a sale in one area may have a 70/30 split (70% for improvements and 30% towards land) while a different area of the county may have a typical 65/35 split (65% for improvements and 35% towards land). If the property is a condo or doesn't own the land the split may be much lower say 75/25. This last example may have some asking, "If I don't own the land, why would I need to pay taxes on the land?" Well, this falls into the category of possessory interest, in that while the building is occupying the land, it can't be used for any thing else or by a different party's sole title. Therefore, the best thing to do, if one is unable to determine on her or his own, is to call the assessor's office and ask what is the current allocation of land value to the parcel. The assessor's number or at least the tax collector's should be listed on the tax bill.
If one must use a third party source, try Redfin. If the property had a relatively resent sale or listing, Redfin may contain the improvement/land value brake down (which may have been pulled from the assessor's records).
